In the printing industry, there are generally two types of inks, dispersion inks and solution inks. Dispersion inks have been widely used throughout the years because they more easily can be formulated. The primary disadvantage of dispersion inks is that their components tend to settle and, as a result, the inks must be agitated on occasion. Although solution inks do not have a settling problem, they are more difficult to produce. Recently, strides have been made in the capability of producing solution inks, but this has led to incompatibility with the systems that are used to apply such inks. For example, in the printhead of a postage meter, an inking pad or roller, hereafter collectively referred to as inking member, will contact the printhead to transfer ink thereto and be removed therefrom so that the inked print head can contact a mailpiece to print an indicia.
There are also two general types of inking members, rechargeable inking members and self containing inking members. In developing solution inks, it has been found that inking members that are acceptable for use with dispersion inks simply are not efficient when used with solution inks. This is because inking members suitable for dispersion inks have pores that are too large. Such large size pores are required to allow dispersed particles to be distributed through the inking member. Additionally, typical inking members for dispersion inks were found to be incompatible with polyglycols, a component of contemporary solution inks. Consequently, it has become evident that if the benefits offered by solution inks are to be realized, inking members must be developed that will enhance the use of such inks.
In this copending applications Rechargeable Inking Pad and Method of Producing a Felted Polychloroprene Foam, and method of Felting Polychloroprene in Reduced Time, methods are disclosed for producing a layer for an ink pad made of open cell felted polychloroprene foam. The felting of polychloroprene had been heretofore considered unattainable because of the resiliency and lack of compression set of polychloroprene. Although the method disclosed in the copending application proved satisfactory, it became evident such methods were lacking if felted foams with more intricate shapes were required.